Papers by Keyword: Nonionic Surfactant

Abstract: Palm fruit bunch (PFB) and palm fruit residue (PFR) are considered as potential raw materials for ethanol production due to their large availability from palm oil industry. However, the presence of lignin can retard the rate of enzymatic hydrolysis. Both PFB and PFR were pretreated with a 10% w/v sodium hydroxide solution. The amounts of their hemicellulose were substantially decreased whereas their lignin contents were slightly reduced. After that, they were hydrolyzed using cellulase from Trichoderma reesei (ATCC 26921) at 50 °C and pH 5. An addition of Tween 80, nonionic surfactant, with 0.25% w/v concentration provided an increase in reducing sugar production about 50.5% at 10 FPU/g PFB cellulase loading, while the addition of Tween 80 with 0.5% w/v concentration increased reducing sugar production by 38.8% at 20 FPU/g PFR cellulase loading. The greater the amount of lignin in the lignocellulosic materials, the higher the dosages of enzyme and surfactant required for the enzymatic hydrolysis. The adsorption of added nonionic surfactant onto the hydrophobic surface of lignin resulted in an increase in the availability of added enzyme to both cellulose and hemicellulose, leading to the enhancement of enzymatic hydrolysis. Additionally, the adsorption of cellulase on PFB and PFR were well fitted with the Freundlich isotherm.

Abstract: Studying the relationship of oil-water IFT and the stability of oil emulsion will further explain oil displacement mechanism in crude oil flooding. In this article, for nonylphenol polyoxyethylene ether can resist multivalence cations, the performance of associative surfactant containing HABS and nonylphenol polyoxyethylene ether (NP), the influence of the improvement of emulsion stability on the interfacial tension were studied by evaluating the interfacial tension and emulsion stability. Results show that nonionic surfactant NP-x (x=4, 6, 10) can improve the tolerance of HABS to NaOH with low concentration, and NP-6 appears the best synergistic effect, when C_NaOH is not more than 1.2wt%, the IFT_eq is lower than 9.9×10^-3mN/m, within the concentration range of the investigation. At the same time, NP-x can improve oil emulsion stability, when C_NaOH is 0.6wt%, C_HPAM is 0.18wt%, total concentration of the surfactant (ω_HABS:ω_NP=8:2) are 0.05wt% and 0.1wt%, decreasing the balance interfacial tension between oil and water can be regarded as the guarantee of the emulsion stability.

Abstract: A new type of sulfonate surfactant (Gn-SHBP) has been prepared by esterification and sulphonation. At 25°C, the surface activity, the effect of NaCl on solution CMC（critical micelle concentration), emulsibility and the tolerance to inorganic salts of sulfonate hyperbranched polymer surfactants were investigated by the methods of surface tension, measuring cylinder and visible-infrared spectrometer. The results show that both surfactants have high surface activity; G2-SHBP exhibit higher surface activity than G1-SHBP with a CMC of 0.2 g/L and a γCMC of 25.36 mN/m; and both perform good emulsify power which exhibit better emulsion stability than SDBS; and high resistance to inorganic salt which can reach up to 260 g/L ( NaCl), 140 g/L(CaCl2) and 190 g/L(MgCl2), respectively.

Abstract: The interaction between the anionic Gemini surfactant Ib and the conventional nonionic surfactant Triton X-100 was investigated. The critical micelle concentrations (cmc) of different mixtures were measured by surface tension measurement at 298 K. The results showed that the cmc of different mixtures at any mole ratio was lower than that of either pure Ib or Triton X-100, indicating synergetic behavior. And the interaction parameter ß values for the mixed micelles were negative, showing attractive interaction between these surfactant molecules. Besides, the micelle aggregation number (N) was measured using a steady state fluorescence quenching method. The N values of the mixed surfactant system were larger than that of pure Ib but lower than pure Triton X-100 at any ratio.

Abstract: In present time, recycled paper from xerographic and laser-printed wastepaper plays an important role as alternatives to paper from virgin pulp because of there good pulp quality and high amount of wastepaper each year. This type of paper is classified as Mixed Office Wastepaper (MOW). The xerographic and laser-printed inks are usually called “toner” that mainly consists of styrene-acrylate copolymer. This work investigated paper recycling by washing deinking processes. Experimental parameters were pulp consistencies, amounts and types of surfactant. The resultant pulp of 1.5%consistency and 0.9 wt% of nonionic surfactant, Triton X-100, is the optimum washing deinking process. The resultant pulps have optical and physical properties closed to non-printed paper. Surfactant concentrations were kept below CMC to provide low ink specks, high brigthness and strength on handsheets. The recycled pulp will be use as a raw material for electrical purpose paper.

Abstract: The effect of surfactant in alkaline slurry for copper chemical mechanical polishing (CMP) was studied through polishing experiments with slurries containing different weight percentage of four nonionic surfactants respectively. The results indicate that properly chosen nonionic surfactants with proper weight percentage could result in little negative influence on the material removal rate, but can help to improve copper wafer surface quality significantly. Alkylphenol ethoxylates was found to be an excellent surfactant for alkaline slurry and a surface roughness of Ra 0.89nm and a material removal rate of 526 nm/min were obtained when polishing with the slurry containing 0.25 wt% alkylphenol ethoxylates, while the surface roughness and the material removal rate were Ra 1.34nm and 525 nm/min respectively when polishing with the origin slurry. The density of polishing defects such as scratches and etch pits decreased significantly. The action mechanism of surfactant was further analyzed based on the experiment results.